Infrared alarm working principle analysis

Infrared alarms are available in both active and passive modes. The active infrared alarm device is an alarm that actively emits infrared rays. When the infrared rays hit an obstacle, they will bounce back and be received by the probe of the alarm. If the probe is detected, the infrared light is still, that is, the red line is continuously emitted and rebounds continuously, then the alarm will not alarm. When a moving object violates this invisible red line, the probe will detect an abnormality and will alarm.

Infrared alarm works

After installing the detector in areas that need to be guarded (such as living room, bedroom, kitchen, hallway, warehouse, store, etc.), if a thief enters the prevention area, the detector will detect the human body's infrared rays and immediately transmit the digital code. The alarm signal, which is received by the infrared alarm installed within -km, immediately sounds a squeaking alarm, scares the thief, reminds the owner, the owner can clear the alarm location according to the alarm light on the panel of the infrared alarm. Go to catch thieves. Some devices also have an automatic memory alarm time function. If the owner is not at home, then when you go home, you can know when the thief is at home.
 

Passive infrared alarm works

The passive infrared alarm is mainly based on the change of infrared energy of the outside world to determine whether someone is moving. The infrared energy of the human body is different from the environment. When a person passes the detection area, the position of the different infrared energy collected by the alarm changes, and then an alarm is sent through analysis. The human body has a constant body temperature, generally around 37 degrees, and emits infrared rays with a specific wavelength of about 10 μm. The passive infrared alarm device works by detecting infrared rays of about 10 μm emitted by the human body. The infrared light emitted by the human body of about 10 μm is reinforced by the Fresnel filter and collected on the infrared sensing source. The infrared sensing source usually adopts a pyroelectric element, which loses the charge balance when receiving the temperature change of the infrared radiation of the human body, and discharges the charge outward, and the subsequent circuit can generate an alarm signal after being detected and processed.

Active infrared report line police working principle

The active infrared alarm is composed of a transmitter and a receiver. The transmitter comprises a power source, a light source, an optical system and the like. Under the action of the power source, the infrared light emitting diode emits an infrared light beam, and is converted into parallel light by the optical system. The receiver includes an optical system, an amplifier, an optical sensor, a signal processor and the like, and is responsible for receiving infrared rays emitted by the transmitter, and converting the optical signal into an electrical signal by the photoelectric sensor, and analyzing and processing the signal to the alarm control. Device.